Semiconductor devices are used in a variety of electronic applications, such as, for example, personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. In order to increase the density of active devices, the active devices are formed on a semiconductor substrate and connected to each other, other devices in a die, or to external devices through in redistribution layers (RDLs) with conductive lines in insulating layers. Interconnects in the RDLs are connected to individual elements in each active device with conductive plugs or contacts formed in an interlayer dielectric (ILD) between the semiconductor surface and the RDL. Passivation layers and post-passivation interconnects provide connection between the RDLs and a connector such as a solder ball, stud, bump or the like. The RDLs and passivation layers are frequently formed using back-end-of-line (BEOL) processes after the production of active semiconductor devices, but prior to singulating dies from a wafer.